File Encrypter

local tArgs = {...}
if fs.exists(tArgs[1]) and not fs.isDir(tArgs[1]) then
  local file = fs.open(tArgs[1],"r").readAll()
  local cryp = "local run = [["
  for i=1,#file do
    cryp = cryp..string.char(string.byte(file:sub(i,i))+1)
  end
  cryp = cryp.."]]\n\n"
  cryp = cryp..[[
  local tbl = {...}
  local exc = ""
  for i=1,#run do
    exc = exc..string.char(string.byte(run:sub(i,i))-1)
  end
  loadstring(exc)(unpack(tbl))
  ]]
  write("Save as: ")
  local dest = read()
  local final = fs.open(dest,"w")
  final.write(cryp)
  final.close()
else
  printError("Incompatible File")
end